In this work in vitro evaluation of the reactivation potency of the newly synthesized reactivators for acetylcholinesterase (AChE; EC 3.1.1.7) is described. Using this method, reactivation potency of 21 potential reactivators of AChE inhibited by the nerve agent sarin has been evaluated. We have confirmed the fact that currently the most promising AChE reactivator, HI-6, is the most effective reactivator of sarin-inhibited AChE. There are only three AChE reactivators-HI-6, TO033 and TO047-able to satisfactorily reactivate sarin-inhibited AChE at the concentration 10(-5) M, which is nontoxic for human use. On the other hand, there are 14 AChE reactivators, that are able to reactivate sarin-inhibited AChE at the concentration 10(-3) M. However, this concentration of reactivator is probably toxic for human use.